But here's the apparent clever bit, built using what is said to be machine learning to understand what else is behind a product, as the app is effectively "unbundling" the content that is usually provided by an OTA.

Similar to other sectors of the industry, such as airline tickets, on big attractions, the OTAs draw a range of products for a specific attraction together to create a specific deal.

In the case of the Eiffel Tower, this might include "skip-the-line" access, second-floor-only entry, etc.

Touring Bird has stripped away the different elements so that users can select which part they want, or build their own package.

As different parts are added or subtracted, the final buying point changes, based on the price.

So, a user might select second floor access from Viator, but when he or she adds skip-the-line to the deal, the seller switches to GetYourGuide.

Other elements that can be added might be a visit in the attraction's restaurant.

* Check out this interview with Lax Poojary, CEO of Touring Bird, at the Arival event in Las Vegas in September 2018.